INVESTIGATIONS OF OZONE-INDUCED INJURY IN FORESTS OF SOUTHERN SWITZERLAND - FIELD SURVEYS AND OPEN-TOP CHAMBER EXPERIMENTS

Studies were conducted during the period 1993-1996 to determine the ex tent of foliar injury on native plant species and black cherry as may be induced by ambient ozone exposures throughout Switzerland. Particul ar emphasis was placed on determining foliar injury in Canton Ticino ( Ti.) situated in the sub-Alpine region of southern Switzerland. Survey s revealed black cherry to be very sensitive exhibiting an adaxial fol iar stipple and leaf reddening at higher elevation plots in the southe rn-most parts of Ti. Open-top chamber investigations confirmed the fol iar response as being due to ambient ozone. Surveys of natural vegetat ion in proximity to air quality monitoring stations throughout the who le of Switzerland revealed many native plants symptomatic with ozone-l ike foliar injury. Fumigation studies within CSTR chambers are being u sed to determine ozone-induced exposure/response relationships. Of the species thus far tested, Viburnum lantana, Morus nigra, Betula pendul a, Rumex acetosa and Prunus serotina appear most sensitive. (C) 1998 E lsevier Science Ltd.